TECHNICAL FIELD
This invention pertains to a system for supplemental transtracheal oxygen therapy including transtracheal catheter devices for providing transtracheal oxygen to spontaneously breathing patients with chronic lung disease and to methods for catheter placement and use. Such devices are medically desirable therapy for patients having a chronic need for oxygen where a catheter can be installed on a semi-permanent out patient basis.
As a result of studies that date back to the 1930's and particularly studies conducted in the 1960's and early 1970's, it has been determined that long-term continuous oxygen therapy is beneficial in the treatment of hypoxemic patients with chronic obstructive pulmonary disease (COPD). In other words, a patient's quality and length of life can be improved by providing a constant supplemental supply of oxygen to the patient's lungs.
However, with the current desire to contain medical costs, there is a growing concern that the additional cost of providing continuous oxygen therapy for chronic lung disease will create an excessive increase in the cost of oxygen therapy. Thus, it now desirable that oxygen therapy, when provided, be as cost effective as possible.
The standard treatment for patients requiring supplemental oxygen is still to deliver oxygen from an oxygen source by means of a nasal cannula. Such treatment, however, requires a large amount of oxygen, which is wasteful and can cause soreness and irritation to the nose, as well as being potentially aggravating. Other undesirable effects have also been reported. Other medical approaches which have been proposed to help reduce the cost of continuous oxygen therapy have been studied.
Various devices and methods have been devised for performing emergency cricothyroidotomies and for providing a tracheotomy tube so that a patient whose airway is otherwise blocked may continue to breathe. Such devices, are generally intended only for use with a patient who is not breathing spontaneously and are not intended for the long-term oxygen supplementation therapy for chronic lung disease. Typically, such devices are installed by puncturing the skin to create a hole through the cricoid thyroid membrane above the trachea through which a relatively large curved tracheotomy tube is inserted. As previously described, the use of such tubes has been restricted medically to emergency situations where the patient would otherwise suffocate due to the blockage of the airway. Such emergency tracheotomy tubes are not intended for long-term oxygen supplementation therapy after the airway blockage is removed.
Other devices which have been found satisfactory for emergency or ventilator airway control are described in U.S. Pat. No. 953,922 to Rogers; U.S. Pat. No. 2,873,742 to Shelden; U.S. Pat. No. 3,384,087 to Brummelkamp; U.S. Pat. No. 3,511,243 to Toy; U.S. Pat. No. 3,556,103 to Calhoun; U.S. Pat. No. 2,991,787 to Shelden, et al; U.S. Pat. No. 3,688,773 to Weiss; U.S. Pat. No. 3,817,250 to Weiss, et al.; and U.S. Pat. No. 3,916,903 to Pozzi.
Although tracheotomy tubes are satisfactory for their intended purpose, they are not intended for chronic usage by outpatients as a means for delivering supplemental oxygen to spontaneously breathing patients with COPD. Such tracheotomy tubes are generally designed so as to provide the total air supply to the patient for a relatively short period of time. The tracheotomy tubes are generally of rigid or semi-rigid construction and of large caliber ranging from 2.5 mm outside diameter in infants to 15 mm outside diameter in adults. They are normally inserted in an operating room as a surgical procedure or in the emergency room during emergency situations, through the cricothyroid membrane where the tissue is less vascular and the possibility of bleeding is reduced. These devices are intended to permit passage of air in both directions until normal breathing has been restored by other means.
Another type of tracheotomy tube is disclosed in Jacobs, U.S. Pat. No 3,682,166 and U.S. Pat. No. 3,788,,326. The catheter described therein is placed over 14 or 16 gauge needle and inserted through the cricothyroid membrane for supplying air or oxygen and vacuum on an emergency basis to restore the breathing of a non-breathing patient. Because of resistance to gas flow created by the small inside diameter of the tube, the air or oxygen is supplied at very high pressures, i.e. from 30 to 100 psi for inflation and deflation of the patient's lungs. The Jacobs catheter, like the other tracheotomy tubes previously used, is not intended for long-term outpatient use, and could not easily be adapted to such use.
Due to the limited functionality of tracheotomy tubes, transtracheal catheters have been proposed and used for long-term supplemental oxygen therapy. For example the small diameter transtracheal catheter (16 gauge) developed by Dr. Henry J. Heimlich (described in THE ANNALS OF OTOLOGY, RHINOLOGY & LARYNGOLOGY, Nov.-Dec. 1982; Respiratory Rehabilitation with Transtracheal Oxygen System) has been used by the insertion of a relatively large cutting needle (14 gauge) into the trachea at the mid-point between the cricothyroid membrane and the sternal notch. This catheter size can supply oxygen up to about 2 to 3 liters per minute at low pressures, such as 2 psi, however this flow rate may be insufficient for patients who have higher oxygen requirements. It does not, however, lend itself to convenient outpatient use and maintenance, such as periodic removal and cleaning, primarily because the connector between the catheter and the oxygen supply hose is adjacent and against the anterior portion of the trachea and cannot be easily seen and manipulated by the patient. Furthermore, the catheter is not provided with positive means to protect against kinking or collapsing which would prevent its effective use on an out patient basis. Such a feature is not only desirable but necessary for long-term, out patient and home care use. Also, because of its structure, i.e. only one exit opening, the oxygen from the catheter is directed straight down the trachea toward the bifrucation between the bronchi. Because of the normal anatomy of the bronchi wherein the left bronchus is at a more acute angle to the trachea than the right bronchus, more of the oxygen from that catheter tends to be directed into the right bronchus rather than being directed or mixed for more equal utilization by both bronchi. Also, as structured, the oxygen can strike the mucous membrane of the carina, resulting in an undesirable sensation and a tendency to cough. In addition, in such devices, if a substantial portion of the oxygen is directed against the back wall of the trachea it may result in erosion of the mucosa in this area, this is also undesirable. Overall, because of the limited output from the device, it may not operate to supply sufficient oxygen during supplemental oxygen therapy when the patient is exercising or otherwise quite active or has severe disease.
Thus, none of the prior art devices are fully suitable for outpatient use on a long-term basis.
It is therefore an objective of the present invention to provide a catheter, catheter insertion system and method for catheter insertion and use which will provide for efficient long-term oxygen therapy, particularly for active patients and severely ill patients with high oxygen requirements at rest.